The present invention relates to an atomizer container for liquid having a suspension of particles to be deposited on a wafer in a deposition chamber. The container and liquid is vibrated ultrasonically with a high voltage drive vibrating transducer to keep the particles in the deposition chamber in suspension. The high voltage drive is shielded to avoid contact with an operator.
Ultrasonic vibration has been used in aerosol generators for agitating the liquid to maintain a suspension of particles.
High voltages are generally needed for the operation of ultrasonic vibration generators, which usually are piezoelectric ceramics or crystals. Contact by an operator with the conductors is to be avoided. The present container is assembled in a manner that maintains a high level of isolation for the high voltage components from the exterior, so that the likelihood of contact by an operator is greatly reduced.
An atomizer container for a liquid that carries a suspension of particles used for deposition on wafers in a deposition chamber is assembled with a piezoelectric ultrasonic transducer on a bottom wall of the container to provide ultrasonic vibrations in the liquid. The particles remain in suspension when the container is ultrasonically vibrated so an aerosol containing the desired particles can be maintained. A high voltage contact assembly is used for connecting the piezoelectric ultrasonic vibration transducer to the voltage source. The connections to the transducer are carried through an insulated housing that reduces the likelihood of an operator contacting any of the components.
The particle suspension is maintained by the vibrational energy, so when the liquid is passed through the atomizer nozzle in order to form an aerosol for deposition of the particles in a deposition chamber. When several different particles are to be deposited in one chamber, a number of liquid containers are provided, each with a different particle suspension or characteristic, and sequential use means that one container may be inactive, with no aerosol generated from the liquid, for a long period of time.
The coupling of the high voltage power to the transducer is surrounded by a well insulated cup or sleeve that connects to the base of the container. The cup or sleeve carries an electrical connector that couples to the ultrasonic piezoelectric transducer. The piezoelectric transducer is in intimate contact with the bottom wall of the container. The likelihood that conductors on one container would be contacted by an operator are thus decreased.